//封装倒计时函数
import {computed, onUnmounted, ref} from 'vue'
import dayjs from 'dayjs'
export const useCountDown=()=>{
    //响应式数据
    const time=ref(0)

    //开启倒计时的函数
    //格式化时间
    
    let timer=null
    const formatTime=computed(()=>dayjs.unix(time.value).format('mm分ss秒'))
    const start=(currentTime)=>{
        
       
        //核心逻辑编写,每隔一秒减1
        time.value=currentTime
       
      timer = setInterval(()=>{
           time.value--

        },1000)
    }
    //组件销毁时，清除定时器
    onUnmounted(()=>{
        timer&&clearInterval(timer)

    })
    return {
        formatTime,
        start
    }
    

}
